In honor of Earth Day, National Geographic is selling prints of some ... photographers have captured some of the world's best images. While many of the photographs featured online and in print ...

Prehistoric time line, geologic time scale, photos, facts, maps, and more from National Geographic. Humans have walked the Earth for 190,000 years, a mere blip in Earth's 4.5-billion-year history.

Veteran astronaut and esteemed astrophotographer Don Pettit has recreated one of his most iconic photos on his most recent mission to space. Pettit took Lightening Bugs in 2012 while on Expedition ...